What to Know About High Blood Pressure and Low Pulse

Whether you are young or old, healthy or not, it is important to be aware of your blood pressure and pulse rate. These two measurements are useful indicators of your general health and how well your heart is working.

Your blood pressure and pulse are closely related and often increase or decrease together. At other times, your blood pressure can change in one direction while your pulse changes in the opposite direction. Understanding more about the combination of high blood pressure and a low pulse will help you know the possible causes and when to see a doctor.

Your pulse rate is the number of pulsations in a minute that you can feel over one of your arteries. The pulsations are usually felt over the radial artery at your wrist or over the carotid artery in your neck. They are caused by your heartbeats and the pulse rate is usually the same as the heart rate. Sometimes not all of the heartbeats can be felt over the artery, causing the pulse rate to be lower than the heart rate.

A normal pulse rate is a range of values, which depends to a large extent on age. Children have higher pulse rates than adults. The normal pulse rate in adults ranges from 60 to 100 beats per minute. A pulse below 60 is considered low.

Your blood pressure is the force of blood as it pushes against the walls of your arteries. Blood pressure is usually measured in the upper arm or wrist with a blood pressure machine. It consists of two numbers: a higher number called the systolic pressure and a lower number called the diastolic pressure.

Like the pulse, normal blood pressure is a range that depends on age. Children have lower blood pressures than adults, for example. But according to the American Heart Association, healthy blood pressure is lower than 120/80. It's considered elevated if the top number is between 120 and 129 and bottom number is less than 80. High blood pressure is 130/80 or higher.

Your body is a complex machine that tries to stay in balance. Because a normal blood pressure is so important for your health, your body constantly strives to maintain your pressure within the normal range. When your blood pressure rises, a reflex called the baroreceptor reflex is triggered in an attempt to lower your pressure. As a result of this reflex, the heart rate becomes slower. So the natural response to any increase in blood pressure is a lower pulse. But this response is not always seen, as various factors may overcome it.

Many high blood pressure medications directly lower your heart rate. If they are unable to fully reduce the blood pressure to normal, then the combination of high blood pressure and a low pulse will occur. These blood pressure medications are especially likely to lower your heart rate:

• Beta blockers, such as metoprolol (Lopressor, Toprol-XL) and atenolol (Tenormin)
• Calcium channel blockers, such as diltiazem (Cardizem, Tiazac) and verapamil (Calan SR, Isoptin SR)
• Clonidine (Catapres)
• Methyldopa (Aldomet)

Some people with high blood pressure also have heartbeat abnormalities that produce a low pulse. In sick sinus syndrome, for example, the part of the heart that produces a normal heartbeat — called the sinus node — does not function as it should. This can lead to a slow heart rate.

Phenylephrine (Neosynephrine) — a medication found in some nose sprays — can produce high blood pressure if sufficient amounts are absorbed into the bloodstream. This medication has no direct effects on the heart, but the increase in blood pressure will sometimes produce reflex lowering of the heart rate. These blood pressure and pulse effects are usually small if you do not take more than the recommended dose.

Major problems within the skull, such as a stroke, tumor or bleeding, may increase the pressure surrounding the brain, a condition known as intracranial hypertension. The body's natural response to intracranial hypertension, especially when severe, is an increased blood pressure and a decreased pulse rate. This is called the Cushing reflex.

A heart attack may produce a low pulse, especially if it involves the inferior part of the heart. This is usually accompanied by low blood pressure, but sometimes high blood pressure occurs instead, especially in people with pre-existing high blood pressure.

A low pulse rate is generally detected by feeling for the pulse in the wrist or neck and counting the number of pulsations in a minute. A low pulse may sometimes cause heart palpitations, weakness, lightheadedness or dizziness.

The only way to be certain that your blood pressure is high is to measure it with a blood pressure machine. An elevated blood pressure usually causes no symptoms unless it is very high — over 180 mm Hg systolic pressure or over 120 mm Hg diastolic pressure. Very high blood pressure can lead to a number of life-threatening conditions, such as a heart attack, stroke, swelling in the brain or ruptured blood vessels.

If you think your pulse is low or your blood pressure is high, see your doctor to find out for sure and to determine the cause and appropriate treatment. Seek immediate medical care if your pulse is less than about 50 beats per minute and you are experiencing dizziness, severe fatigue or fainting. You should also see a doctor if your systolic blood pressure is above 180 mm Hg or your diastolic blood pressure is higher than 120 mm Hg.

Also obtain immediate medical attention if you have any of these symptoms, no matter what your pulse or blood pressure values are:

• Chest or back pain
• Shortness of breath
• Heart palpitations
• Dizziness or lightheadedness
• Confusion
• Loss of consciousness
• Weakness or paralysis
• Numbness or other changes in sensation
• Difficulty speaking or swallowing